This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objectives of this subproject are to: elucidate the prospective role of ovulation in the etiology of ovarian cancer of surface epithelial origin with the goal of devising preventive measures (sheep model);and improve treatment responses by overcoming drug resistance and nonspecific toxicities (human SKOV-3 and OVCAR-3 cell lines;athymic mouse xenograft model).